Combustion apparatus

ABSTRACT

THE OUTLET FROM A BURNER IS DIVIDED INTO A NUMBER OF ALTERNATING SLIT-SHAPED DISCHARGE OPENINGS FOR FUEL GAS AND FOR AIR ARRANGED SIDE BY SIDE. A PLURALITY OF SUCH BURNERS OPEN INTO A FIRE CHAMBER IN SUCH A MANNER THAT THE AXES OF FLOW THEIR OUTLET ARE OFFSET FROM THE CENTER OF THE FIRE CHAMBER.

JAIL .19, "1971 Filed Dec. 11. 1968 RYUJIRO MOMODA A!- comsusnon APPARATUS 2 Shts-Sheet 2 INVENTOR S vuIoR momma mRDsm wwmg W auwwm ATTORNEY) United States Patent 01 3,556,701 Patented Jan. 19, 1971 3,556,701 COMBUSTION APPARATUS Ryujiro Momoda and Hiroshi Yanabu, Nagassaki-shi, Japan, assignors to Mitsubishi Jukogyo Kabushiki Kaisha, Tokyo, Japan Filed Dec. 11, 1968, Ser. No. 782,892 Int. Cl. F23c /10 US. Cl. 431-181 2 Claims ABSTRACT OF THE DISCLOSURE The outlet from a burner is divided into a number of alternating slit-shaped discharge openings for fuel gas and for air arranged side by side. A plurality of such burners open into a fire chamber in such a manner that the axes of flow from their outlet are offset from the center of the fire chamber.

SUMMARY OF THE INVENTION The present invention relates to a combustion apparatus using a low calorific value gas such as blast furnace gas.

It is generally said that rapid mixing of air or oxygen for combustion with a fuel gas is most important for rapid and complete combustion. Rapid mixing of a large amount of fuel gas having a lower calorific power such as blast furnace gas with air has hitherto been regarded as very difficult.

The principal object of the present invention is to overcome such difficult and to promote the mixing of a low calorific gas with air thereby enabling a reduction in the size a fire chamber which previously has been designed in consideration of the long flames generated and further preventing combustion losses.

According to the present invention, a plurality of burners each having a number of slit-shaped discharge openings for fuel gas and air from a blast box are arranged in alternating side by side relationship with their discharge openings directed into a fire chamber so that the axes of flow from their openings are offset from the center of the fire chamber. Thus rapid mixing of low calorific gas with air can be obtained.

Preferred embodiments of the invention will be described in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a burner according to the invention with compartment partition walls removed;

FIG. 2 is a sectional view of the burner, taken along the line IIII of FIG. 1;

FIG. 3 is a schematic plan view illustrating an arrangement of the burners of FIGS. 1 and 2 in the fire chamber of a boiler;

FIG. 4 is a schematic elevational view illustrating another arrangement of the burners in the fire chamber of a boiler; and

FIG. 5 is a schematic plan view illustrating a further arrangement of the burners.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIGS. 1 and 2, the inner space of an enclosure 1 for a burner is divided by partition walls 2 into a number for slit-shaped discharge openings 3 of fuel gas and discharge openings 4 for air which are arranged in alternating side by side relationship. In the figures two assemblies of discharge openings 3 and 4 are arranged one above the other in such a way that the Openings 3 of one assembly are superjacent to the openings 4 of the other assembly. Fuel gas from a blast box 5 is discharged from the discharge openings 3 as indicated with arrows 6 while air supplied through aperture 10 in the enclosure 1 flows within passages 8 each formed between the enclosure 1 or the blast box 5 and a compartment partition walls 7 surrounding them is discharged from the discharge openings 4, as indicated with arrows 9. Four burners B having such an arrangement of the discharge ojenings 3 for fuel gas and of the discharge openings 4 for air are provided at four corners in the fire chamber F of a boiler as shown in FIG. 3. Those burners B are so directed that their longitudinal axes deviate or are offset at a certain dimension from the center the fire chamber whereby fuel gas and air which has been discharged from the burners B together may form a vortex in center of the fire chamber F.

In FIG. 4, there are shown the burners B provided at four corners of the fire chamber F of a boiler.

In the above embodiments, fuel gas and air for effecting combustion are discharged at a certain velocity v from the discharge openings 3 and the discharge openings 4 arranged side by side in each burner B and make a whirling motion at a whirling angular velocity W=v/ r (r: radius of whirl). The whirling angular velocity W of fuel gas and air discharged with a certain width into the fire chamber F from the discharge openings 3 and 4 is higher in the neighborhood of the center of the fire chamber where the radius r of whirl is small and lower in the neighbor hood of the periphery of the fire chamber where the radius r of whirl is large so that a difference in the phase of flow arises at places of different radii of whirl. This results in a rapid stirring up of the fuel gas and air, and, therefore, in a rapid and complete combustion of the fuel gas.

In the above embodiments, the burners B are provided at the four corners of a fire chamber F. However, these burners B can also be provided in the wall K of a fire chamber discharging in the direction of arrows B as shown in FIG. 5.

From the foregoing it will be easily understood that rapid mixing of a low calorific gas with air for combustion can be quite satisfactoril made and consequently rapid and complete combustion can also be favorably performed, whereby the fire chamber of a boiler, which has hitherto been designed in av large size can be designed in a smaller size and combustion losses can be reduced.

What is claimed is:

1. An apparatus for effecting combustion between a low califoric gas and air, comprising walls forming a fire chamber, a plurality of burners located in said walls for directing gas and air into said fire chamber, said burners comprising a housing, a plurality of partitions disposed within said housing and dividing said housing into a number of passages terminating in slit-shaped discharge openings disposed in side-by-side relationship at the outlet end of said burner within said fire chamber, said passages arranged to be supplied with gas and air so that said gas discharge openings and said air discharge openings are disposed in alternating relationship, the axes of flow of fuel gas and air from said discharge openings being directed generally toward but offset from the center of said fire chamber, and each said burner comprises two assemblies of said passages with one said assembly disposed superjacent the other said assembly, and said passages in said assemblies arranged whereby said fuel gas discharge openings in one assembly are vertically aligned above said air openings in the other.

2. An apparatus for effecting combustion between a low calorific gas and air, comprising walls forming a fire chamber, a plurality of burners located in said walls for directing gas and air into said fire chamber, said burners comprising a housing, a plurality of partitions disposed within said housing and dividing said housing into a number of passages terminating in slit-shaped discharge openings disposed in side-by-side relationship at the outlet end of said burner within said fire chamber, said passages arranged to be supplied with gas and air so that said gas discharge openings and said air discharge openings are disposed in alternating relationship, the axes of fiow of fuel gas and air from said discharge openings being directed generally toward but offset from the center of said fire chamber, and at least four said burners are disposed in spaced relationship in the walls of said fire chamber, and the flow axes of two of said burners are arranged tangentially to a first circle concentric with the center axis of said fire chamber, and the flow axes of the other two said burners being disposed tangentially References Cited UNITED STATES PATENTS 4/1959 Seidl 431173X 2/1966 Beyer 431174X 1 EDWARD G. FAVORS, Primary Examiner US. Cl. X.R. 4315 

